浅谈挖掘机的使用

挖掘机是土石方工程施工的主要机械之一，能在坚实的土壤和爆破后的岩石中进行挖掘作业，还可以更换各种工作装置，在建筑工程施工中得到广泛的应用，为提高挖掘机的使用效率就要注意挖掘机的正确使用。     

全氟辛基磺酸酸度函数H0的测定

It is reported in this paper that the acidity function H_0 of perfluorooctanesulfonic acid (POSA) is -12.11±0.03, which was measured first time by ~1H NMR method, in term of the α-H chemical shifts of the acid-ether systems, using 98% to 100% H_2SO_4 as reference standards. This method provides a new procedure for measuring the H_0 value of solid perfluoroalkanesulfonie acid C_nH_(2n+1)SO_3H(n>7).     

Preparation of a Star Network PEG-based Gel Polymer Electrolyte and Its Application to Electrochromic Devices

A star network polymer with a pentaerythritol core linking four PEG-block polymeric arms was synthesized, and its corresponding gel polymer electrolyte based on lithium perchlorate and plasticizers EC/PC with the character being colorless and highly transparent has been also prepared. The polymer host was characterized and confirmed to be of a star network and an amorphous structure by FTIR, ^1H NMR and XRD studies. The polymer host hold good mechanical properties for pentaerythritol cross-linking. Maximum ionic conductivity of the prepared polymer electrolyte has reached 8.83 × 10 ^-4 S·cm^-1 at room temperature. Thermogravimetry （TG） of the polymer electrolyte showed that the thermal stability was up to at least 150 ℃. The gel polymer electrolyte was further evaluated in electrochromic devices fabricated by transparent PET-ITO and electrochromically active viologen derivative films, and its excellent performance promised the usage of the gel polymer electrolyte as ionic conductor material in electrochrornic devices.     

由水杨醛合成5,10,15,20—四（2—羟基苯基）卟啉的色谱法研究

１引言卟啉类化合物有多种重要用途，它是制造光敏、气敏及ＬＢ膜的新型材料，也是高灵敏度的光度试剂。近年来，医学发现细胞易富集该类化合物，因而卟啉类药物研究日益广泛。作者以高效液相色谱法为分析手段，考察了水杨醛在不同条件下与吡咯反应生成５，１０，１５，２０－四（２－羟基苯基）卟啉（简称ＴＨＰＰ）的产率。２实验部分２．１仪器与试剂日本岛津ＬＣ－６Ａ液相色谱仪，配有ＳＰＤ、６ＡＶ紫外可见光检测器及ｐＨＳ－２型酸度计（上海）。ＨＰＬＣ甲醇（上海吴泾化工厂），水杨醛、水杨酸及ＴＨＰＰ标准品购于Ｓｉｇｍａ公司…     

低聚苯乙烯基亚膦酸氧化反应研究

用稀硝酸和过氧化氢将低聚苯乙烯基亚膦酸(PSPUA)氧化为相应的膦酸(PSPNA),并用红外和质谱表征.结果表明过氧化氢仅能部分氧化PSPUA,稀硝酸可将PSPUA完全氧化为PSPNA.氧化反应的最佳条件为:10%的稀硝酸,85℃,氧化反应2h.     

链接基团对固载手性Salen Mn(m)催化不对称环氧化反应的影响

制备了二胺和二酚修饰的晶态有机聚合物-无机杂化载体低聚苯乙烯基膦酸-膦酸氢锆(LCZSPP)轴向固载手性Salen Mn(Ⅲ)催化剂,将其应用于非官能烯烃的多相不对称环氧化反应.研究了两类轴向连接基团及助催化剂在催化不对称环氧化反应中的影响.结果表明,通过二胺为链接基团固载的催化剂在加入轴向助剂(NMO)的情况下,转化...     

中师物理教学中的课堂提问

讨论中师物理课堂提问的意义，分析其种类，指出要求。     

关于我国汽车水性涂料的前景及其环保性能的探讨

与传统溶剂涂料相比较，汽车水性涂料在环保、安全、节能、经济、原料等方面具有突出的优势。在此，简单介绍我国汽车水性中涂和面漆的最新研究状况，并对其应用前景进行展望。